code: def test_forward_gpu(self):
      self.l.to_gpu()
      self.check_forward(cuda.to_gpu(self.x))
  
file_path: chainercv/tests/links_tests/connection_tests/test_separable_conv_2d_bn_activ.py
imports: import unittest
  import chainer
  from chainer.backends import cuda
  from chainer.functions import relu
  from chainer import testing
  from chainer.testing import attr
  from chainercv.links import SeparableConv2DBNActiv
  import numpy
label_desc: Use image node_id 4 for calling the TestSeparableConv2DBNActiv obj's underlying member method code with example usage: obj.test_forward_gpu() without return types